JSON boolean values are stripped

[AndyMcKenna]

Describe the bug In v1.18.0, when minimizing JSON with a boolean property, the true/false value is stripped in the output

To Reproduce Modify the TestScripts.Json test method

        public void Json()
        {

            input = @"
<script type=text/javascript>
var js=""somevar"";
</script>
<script type=application/json>{
    ""@context"": ""http://schema.org/"",
    ""@type"": ""WebSite"",
    ""url"": ""https://domain.ext"",
    ""name"": ""Name Site"",
    ""isChecked"": true,
    ""alternateName"": null
}</script>";
            output = @"<script>var js=""somevar""</script><script type=application/json>{""@context"":""http://schema.org/"",""@type"":""WebSite"",""url"":""https://domain.ext"",""name"":""Name Site"",""isChecked"":true,""alternateName"":null}</script>";
            equal(minify(input), output);
        }

Minified output or stack trace From the test:

<script type=text/javascript>
var js="somevar";
</script>
<script type=application/json>{
    "@context": "http://schema.org/",
    "@type": "WebSite",
    "url": "https://domain.ext",
    "name": "Name Site",
    "isChecked": true,
    "alternateName": null
}</script>
inner_js: warning : Invalid JSON JavaScript nodes encountered during output
======
OUTPUT
------
<script>var js="somevar"</script><script type=application/json>{"@context":"http://schema.org/","@type":"WebSite","url":"https://domain.ext","name":"Name Site","isChecked":,"alternateName":null}</script>
========
EXPECTED
--------
<script>var js="somevar"</script><script type=application/json>{"@context":"http://schema.org/","@type":"WebSite","url":"https://domain.ext","name":"Name Site","isChecked":true,"alternateName":null}</script>

I tracked it down to true getting changed to !0 which looks like it's controlled by TreeExpressions.BooleanLiteralsToNotOperators but I can't find what setting sets that flag on KillSwitch

[trullock]

What are we saying is the issue here, that it outputs empty (surely this) or that it outputs 0! rather than true?

[AndyMcKenna]

That it outputs empty, yeah. It's outputting empty because the true gets converted to !0 along the way and that's what is causing the invalid JSON node warning

[trullock]

yep, on it.